Flags have been often used as rallying issues at some point of battles; squaddies could gather around their colours for morale

https://edwinqkjo648.swiftnestly.com/posts/a-collector-s-dream-the-fascinating-world-of-civil-war-flags-2

Flags had been frequently used as rallying aspects for the period of battles; infantrymen would gather round their colorings for morale give a boost to while faced with overwhelming odds.